Note
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Stairs Demo#
This example demonstrates the use ofstairs for stepwiseconstant functions. A common use case is histogram and histogram-like datavisualization.
importmatplotlib.pyplotaspltimportnumpyasnpfrommatplotlib.patchesimportStepPatchnp.random.seed(0)h,edges=np.histogram(np.random.normal(5,3,5000),bins=np.linspace(0,10,20))fig,axs=plt.subplots(3,1,figsize=(7,15))axs[0].stairs(h,edges,label='Simple histogram')axs[0].stairs(h,edges+5,baseline=50,label='Modified baseline')axs[0].stairs(h,edges+10,baseline=None,label='No edges')axs[0].set_title("Step Histograms")axs[1].stairs(np.arange(1,6,1),fill=True,label='Filled histogram\nw/ automatic edges')axs[1].stairs(np.arange(1,6,1)*0.3,np.arange(2,8,1),orientation='horizontal',hatch='//',label='Hatched histogram\nw/ horizontal orientation')axs[1].set_title("Filled histogram")patch=StepPatch(values=[1,2,3,2,1],edges=range(1,7),label=('Patch derived underlying object\n''with default edge/facecolor behaviour'))axs[2].add_patch(patch)axs[2].set_xlim(0,7)axs[2].set_ylim(-1,5)axs[2].set_title("StepPatch artist")foraxinaxs:ax.legend()plt.show()
baseline can take an array to allow for stacked histogram plots
Comparison ofpyplot.step andpyplot.stairs#
pyplot.step defines the positions of the steps as single values. The stepsextend left/right/both ways from these reference values depending on theparameterwhere. The number ofx andy values is the same.
In contrast,pyplot.stairs defines the positions of the steps via theirboundsedges, which is one element longer than the step values.
bins=np.arange(14)centers=bins[:-1]+np.diff(bins)/2y=np.sin(centers/2)plt.step(bins[:-1],y,where='post',label='step(where="post")')plt.plot(bins[:-1],y,'o--',color='grey',alpha=0.3)plt.stairs(y-1,bins,baseline=None,label='stairs()')plt.plot(centers,y-1,'o--',color='grey',alpha=0.3)plt.plot(np.repeat(bins,2),np.hstack([y[0],np.repeat(y,2),y[-1]])-1,'o',color='red',alpha=0.2)plt.legend()plt.title('step() vs. stairs()')plt.show()
References
The use of the following functions, methods, classes and modules is shownin this example:
Tags:plot-type: stairslevel: intermediate
Total running time of the script: (0 minutes 1.965 seconds)